1. Field of the Invention
The present invention relates to a light device, and more particularly to an intelligent light device for a vehicle which adjusts the illumination level of a light body according to the illumination level of the surrounding environment.
2. Description of Related Art
Cycling has become a trend all over the world since it is energy-saving and zero-pollution. In order to ride the bicycle safely, a light device is usually disposed on the bicycle for illumination and warning purposes.
A conventional light device for a bicycle comprises a circuit and a light-emitting diode (hereinafter referred to as LED). The circuit is connected to the LED. The LED is connected to a cadmium sulfide photoresistor (hereinafter referred to as CDS). The CDS is connected to a switch and has a photosensor which senses the illumination level of the surrounding area thereof. The switch selectively connects or breaks an electrical circuit of the conventional light device for a bicycle according to the vibration level of a bicycle so as to control the illumination of the LED, wherein the switch connects the electrical circuit of the conventional light device for the bicycle when the bicycle is vibrated. Under this arrangement, the illumination of the LED is controlled by the photosensor of the CDS and the switch. Although the conventional light device for a bicycle turns on or off according to the illumination level of the surrounding area, the illumination level of the LED cannot be adjusted to an appropriate illumination level because of the structure of the switch. In addition, the photosensor of the CDS is not able to sense the illumination level within a predefined area.
As a result, the disadvantages of the conventional light device for a bicycle are further detailed as following.
Firstly, the illumination level of the LED cannot be adjusted to the appropriate illumination level corresponding to the surrounding environment. Therefore, the illumination level of the LED might not be enough to illuminate a front area of a bicycle in one case so as to cause a bike accident; in another case, the illumination level of the LED might be excess so as to cause a waste of the power.
Secondly, the conventional light device for a bicycle needs to be equipped with a power source with a high capacitance because the conventional light device for a bicycle sometimes keeps turning on even when the illumination is not necessary. The power source with the high capacitance is either expensive or largely sized and weight. Therefore, the conventional light device for a bicycle is inconvenient and not economic for a user.
Thereby, the present invention has arisen to mitigate and/or obviate the disadvantages of conventional light device for a vehicle.